Tenofovir Alone Versus Tenofovir With Emtricitabine to Treat Chronic Hepatitis B

Chronic hepatitis B is a major cause of cirrhosis, end-stage liver disease and hepatocellular carcinoma and affects approximately 1.25 million Americans. Six medications have been licensed for use in chronic hepatitis B in the United States, but their relative benefit and long-term efficacy remain unclear. In previous studies, we have shown that maintained suppression of hepatitis b virus DNA (HBV DNA) can be achieved with nucleoside analogues and that suppression is associated with marked improvements in disease. In this randomized study, we propose to evaluate long-term therapy with tenofovir alone or in combination with emtricitabine (FTC). Forty treatment-naive patients with chronic hepatitis B will be enrolled in the primary study. After medical evaluation and liver biopsy, patients will be stratified by hepatitis B e antigen (HBeAg) status and randomized to receive either tenofovir alone or in combination with FTC. Treatment will be continued long-term (at least four years) and patients will be carefully monitored for side effects, serum aminotransferase and HBV DNA levels. Patients will undergo repeat liver biopsy and assessment of antiviral resistance at 1 and 4 years. The primary endpoint of therapy will be the maintained suppression of HBV DNA to below 10(2) copies/ml (lower limit of detection of current assays). The study will assess the relative efficacy and safety of combination versus mono-therapy. A separate group of 60 previously treated patients will also be enrolled and randomized to mono- or combination-therapy to assess the safety profile of these agents. The primary analysis will be conducted on the entire study cohort.